Bridge for stringed instruments.



No. 727,203. PATENTED MAY 5, 1903.

' S. G. ROBERTS & F. G. POTTER.

BRIDGE FOR STRINGED INSTRUMENTS. APPLICATION rILnb AUG. 1, 1902.

10 MODEL.

2 SHEETS-SHEET 1.

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. I PATENTED MAY 5,1903. s. 0. ROBERTS & F. 0. POTTER. BRIDGE FOR STRINGED INSTRUMENTS.

APPLICATION FILED AUG. 1, 1902.

2 SHEETS-SHEET 2.

10 MODEL.

UNITED STATES Patented. May 5, 1903.

PATENT OFFICE.

SAMUEL C. ROBERTS AND FRANK O. POTTER, OF SPRINGFIELD,

MASSACHUSETTS.

BRIDGE FOR STRINGED INSTRUMENTS.

SPECIFICATION forming part of Letters Patent No. 727,203, dated May 5, 1903.

Application filed August 1, 1902'. Serial No. 117,947. (No model.)

To all whom, it ntcog concern:

Be it known that we, SAMUEL O. ROBERTS and FRANK O. POTTER, citizens of the United States, and residents of Springfield,in the county of Hampden and Commonwealth of Massachusetts, have invented a new and usefulBridge forStringed Instruments, of which the following is a specification.

Our invention relates to improvements in bridges for stringed instruments,partic ularl y guitars and mandolins,'in which means for independent vertical or longitudinal adjustment of string-supporting members are employed either with or without certain other features, all as hereinafter fully' described and especially claimed; and the objects of our improvement are, first, to provide independently-operating devices for raising or lowering the strings atthe bridge; second, to provide such devices for moving the bearing-points of the strings at the bridge toward or away from the frets; third, to furnish a plurality of pressure-bearings for a single string; fourth, to provide means for maintainin g the same distance between the stringsupport or bearing-point and the pressure member regardless of the horizontal position of said support, and, fifth, to provide a practicable and efficient bridge made up of independent adjustable parts arranged compactly for convenient manipulation, whereby the desired results are obtained. lVe attain these objects by the means illustrated in the accompanying drawings, in which Figure 1 is a plan view of our bridge mounted on a guitar, only the base of the neck of the guitar and lower terminals of the strings being shown; Fig. 2, an enlarged plan View of the bridge, showing four of the six slides in two different positions or conditions; Fig. 8, a front edge view of said bridge; Fig. 4., a bottom view of the same; Fig. 5, a cross-section on lines a; as looking in the direction of the arrow, Fig. 2; Fig. 6,-a side view of one of the slides; Fig. '7, a rear view of a pres sure bar or plate having a plurality of openings for each string; Fig. 8, a side view of a slide equipped with an independent pressure member or post; Fig. 9, a rear view of the same, and Fig. 10 a plan view of a slightlymodified form of slide.

instrument which will give the desired results in perfection of tone with such a bridge the advantages accruing from the use of our invention will readily be perceived. Most bridges of the old style are too high and hold the strings too far above the frets, thus providing an excessive amount of resistance onthe part of the strings and producing hard fingering. Furthermore, an increase of tension on a string beyond a certain limit, resulting from forcing it down onto the frets, tends to make false tones and to render an incorrect representation of the finger-board. Again, different material used in the construction of the strings necessarily causes the tension to vary. On the other hand, a string which is bridged too low is liable to rattle against a fret adjacent to that upon which it is pressed. Then, too, if the bearing-point of a string at the bridge is not in the proper position, longitudinally considered, the string will give a tone which is too sharp or fiat, ac cordiugly as said point is farther from or nearer to the frets than thecase demands.

From the above it is clear that delicate twoway adjustment of the bridge or constituent parts thereof is of great ad vantage,and we will now proceed to describe the means by which such adjustment is obtained.

In Fig. l the body A of aguitar is shown with a part of the neck 13 at one end and a tailpiece O, to which the strings may be said to be anchored, at the other end. Six strings are represented at D, said strings being fastened in any convenient manner to the tailpiece 0 and from there passing to the neck B over the fret-s E on said neck. So far the parts are old and well known, and corresponding parts of a mandolin or other stringed instrument of a similar character may be substituted. .The bridge shown in this figure comprises a basea, generally of hard wood, slides I), provided with supports or hearingscrews 0 and reciprocatingly mounted in said base, means to hold said slides to the base,

a pressure member or bar d, and a rod e, over of substantially the same width as the slide and of proper depth to bring the upper surface of said slide a trifle above the level of the top of the base. The depressions a open at the front into recesses a, formed in the corresponding edge of the base, said recesses being shown a little narrower than the depressions. These recesses are for the purpose hereinafter explained.

The string-supports 0 preferably consist of threaded shanks provided with narrow heads, in each of which is a central notch c. The support or bearing-screw o is threaded into a suitable opening in the slide 17 near the front end of the same.

As a convenient means for fastening the slides 12 after being adjusted to the base a screws f and washers g may be employed, each of the former being located between each pair of slides and threaded at its lower end into a narrow plate h, let into the bottom of said base. Each washer g is interposed between the head of its screwf and portions of two adjacent slides, said washer being large enough to extend over onto the slides, or each slide can be slotted, as shown at Z) in Fig. 10, and a screwf passed through this slot into the plate below to hold the slide in place, in which case a washer may or may not be used. The distance between the tops of the base a and slides b in the preferred arrangement as first described is so slight as to be scarcely perceptible-just enough to permit the washers to bind on the slides; but when slotted slides with a screw for each are employed the thickness of the former is not material.

The pressure member may consist of asimple bar d, spanning the slides 13 and attached to the base by screws 2', which pass through said bar and enter the base at each side of each slide, washersj being employed between the ends of the bar and the base to give the proper elevation to-the former. This elevation can be altered by using thicker or thinner washers or a plurality of the same.

When more delicate adjustment of the strings D is required than can be afforded by the bar d, it may be replaced with a pressure member or plate d, having therein aplurality of bearing points or openings 01'' for each string. The plate d is mounted on the base in a similar manner as the bar d, with the exception that only two screws 2' are employed, one at each end. Here the strings D may pass beneath the pressure-plate d in the same way that they pass beneath the pressure-bar d, or they can be run through such of the holes or openings (1" as will give the best re sults. Ordinarily the adjustment of the strings consequent upon changing the positions of the slides Z) and supports 0 is sufficient, regardless of the form of pressure member; but in some instances more adjustment than is thereby afforded is desirable, and the plate d then becomes useful. The openings (1 in the plate at which correspond to a given string are arranged one above the other, the upper openings onlybeing serviceable in connection with supports 0 of unusual height.

We prefer to construct the slide 1) with a lug b" on one face, or what maybe termed the bottom thereof, at the front end and to extend the threaded opening for the support 0 clear through this lug. When the slides are inserted in the base with their lugs down, the latter are out of the way in the recesses a, in which they operate freely as said slides are adjusted longitudinally, and the supports 0 are screwed into the tops of the slides. The lugs 19 are narrower than the slides b, so as to permit the latter to have a bearing at the sides of the recesses a. In Figs. 1, 5, and 7 the slides are shown with their lugs turned downward, as are also the two central slides in Figs. 2, 8, and 4.

If a greater elevation of one or more strings D is desired than can be afforded by the supports 0 when arranged as above described and screwed up as high as possible, loosen such screwsfas is necessary and remove the slides 12 which correspond with the low wires from the base a, take out the supports 0 from the removed slides and screw them into the bottoms of the lugs b", and replace said supports in inverted positions in said base. the supports 0 have the same amount of adjustment as before plus the height of the lugs 19. The two end slides shown in Figs. 2, 3, and 4 are arranged with their lugs turned upward.

Slides may be utilized which do not.have the lugs h; but the range of adjustment is thereby materially decreased.

In order to retain practically the same distance between the supports and the pressure member, an independent pressure member can be furnished for each slide, the same consisting of a postd, rising from the slide back of the support 0, as shown in Figs. 8 and 9. This pressure-post may be screwed intothe slide from either face similarly to the support, and since it moves with said slide and support, substantially the same distance between bearing-points for the string is always maintained. Holes or openings d in the post afford bearing-points for the string and permit it to be held at different elevations, as in the case of the plate cl. A post cZ is required for each slide, and no other pressure member is needed. The other pressure members are stationary, and when a slide is moved the distance between bearing-points on pressure member and support changes suf- Now IIO

ficiently to affect, it may be, the tone of the string, a result not apparent when the pressure member moves with the slide.

The operation of the several members which constitute our invention will be understood from the foregoing description; but a general explanation of the bridge as a whole follows. Assuming that the parts are the same and stand, as shown in Fig. 1, with the strings D in place, so far as their tailpiece connection or anchorage is concerned, it is first necessary to get said strings under the pressurebar d, which holds them down or depresses them, and over the supports 0, which hold them up. It is to be understood that the opposite ends of the strings are held in the usual and well-known manner, which need not be described here. Now if one of the strings is too close to the frets B lift it out of the notch c, screw up the support 0 the proper distance, and replace said string in the notch. If too far above the frets, repeat the operation, only screw down said support. Should it not be possible to sufficiently elevate the string by screwing up the support to its full height, invert the slide in the manner hereinbefore described and then adjust the support. To lengthen or shorten the tone-producing portion of a string, loosen the screwf that holds the slide 1) which is associated with said string, push said slide backward or forward, and retighten said screw. VVhatis true of one string is true of all in so far as their adjustment is concerned.

Vhen the pressure-plate cl is used in place of the bar d and it is desired to raise or lower a given string at this point, the string must be unfastened at one end, disengaged from said plate, and passed beneath the same or through whichever one of the holes 61 is necessary. So, too, with the pressure-post d', only the string cannot pass beneath the pressure member in this case.

The notch c in the support 0 not only serves to center the engaging string, but also to prevent the support from turning when said string is lodged therein.

We have set forth a practical embodiment of our invention and presented it in the preferred form, but do not Wish to be restricted or confined to the exact construction or arrangement herein shown and described, as changes other than those specified may be made without violating the spirit of said invention.

WVhat we claim as our invention, and desire to secure by Letters Patent, is-

1. .A bridge for stringed instruments, comprising independent vertically-adjustable supports for the strings of the instrument, and invertible sliding members for said supports.

2. A bridge for stringed instruments, comprising independent verticallyadjustable supports for the strings of the instrument, and invertible sliding members for the supports, said supports being notched at the top.

3. A bridge for stringed instruments, comprising independent horizontally-adjustable invertible sliding members with supports for the strings of the instrument, carried thereby, said sliding members being adapted to be held in position by frictional contact or surface ongagement.

4. A bridge for stringed instruments, comprising independent, vertically and horizontally adjustable supporting members for the strings of the instrument.

5. The combination, inabridgeforstringed instruments, with a suitable base, of a slide provided with a vertically-adjustable stringsupport, mounted for longitudinal adjustment in or on said base.

6. The combination, in a bridge for stringed instruments, with a suitable base, of a slide provided with a vertically-adjustable stringsupport, mounted for longitudinal adjustment in or on said base, and means to secure said slide in position.

'7. Thecombination,inabridge forstringed instruments, with a suitable base having depressions extending partly through the same from above, of a plurality of slides provided with string-supports, mounted for longitudinal adjustment in said base depressions, and screws and washers arranged to secure said slides in place, said screws being threaded to stationary parts, substantially as set forth.

8. The combination, in abridge for stringed instruments, with a suitable base, of an invertible slide having a lug on one face, mounted in or on said base, and a string-support adapted to be engaged with either said slide or lug.

9. The combination, in abridge for stringed instruments, with a base having depressions and slots therein, of a plurality of invertible,

slides provided with lugs on one face of each,

and vertically adjustable" string supports adapted to be engaged with either the slides or lugs, said slides being mounted in said depressions with said lugs in said slots when the slides are not inverted.

10. The cornbinatiomin a bridge for stringed instruments, with a tailpiece, of a suitable base and vertically-adj ustable string-supportinstruments, with a suitable base and vertically and horizontally adjustable string-supporting members mounted therein or thereon,

of a pressure member mounted to press down thestrings between their anchorage and'said supporting members.

13. The eombination,in abridge forstriuged instruments, With a suitable base and stringsupporting members mounted therein or thereon, of a pressure member mounted to press down the strings between their anchorage and said supporting members, having a plurality of vertically-arranged bearings for each of said strings.

1-1. The combination,in a bridge forstringed instruments, with a suitable base and vertically-adjustable string-supporting members mounted therein or thereon, of a pressure member mounted to press down the strings between their anchorage and said supporting members, having a plurality of vertically-arranged bearings for each of said strings.

15. The combination,in abridge fox-stringed instruments, with a suitable base and horizontally-adjustable string-supporting members mounted therein or thereon, of a pressure member mounted to press down the strings between their anchorage and said supporting members, having a plurality of vertically-arranged bearings for each of said strings.

16. The eombination,in a bridge forstringed instruments, with a suitable base and vertically and horizontally adjustable string-supporting members mounted therein or thereon, of a pressure member mounted to press down the strings between their anchorage and said supporting members, having a plurality of vertically-arranged bearings for each of said strings.

17. The combinatiomin abridge forstriuged instruments, with a suitable base, of a slide mounted for adjustment; in or on said base, a string-support carried by said slide, and a pressure member also carried by the slide.

18. The combination,in abridge forstringed instruments, with a'suitable base, of an invertible slide provided with a lug on one face, mounted for adjustment in said base, astringsupport adapted to be engaged with either the slide or log, and a pressure member adapted to be engaged with the slide from either face.

19. The combination,in a bridge for stringed instruments, with a suitable base, of a slide mounted in or on said base, a string-support carried by said slide, and a pressure member also carried by the slide and having a plurality of vertically-armnged bearing-points.

In testimony whereof We have signed our names to this specification in the presence of two subscribing witnesses.

SAMUEL C. ROBERTS. FRANK C. POTTER.

\Vitnesses:

STEPHEN I. TAFT, J r., A. O. FAIRBANKS. 

